Women with lupus / antiphospholipid syndrome have circulating antiphospholipid antibodies and are at high risk for recurrent pregnancy loss and pregnancy complications such as, preterm labor and preeclarnpsia. Since antiphospholipid antibodies can target the placenta, the aim of this project is to determine the mechanisms by which these antibodies impact the function and survival of placental trophoblast cells. These studies may lead to new diagnostic and treatment strategies.